MOF‐Derived Oxygen Vacancy‐Rich Co/CoO@NC‐CNTs Hybrid Electrocatalyst for Oxygen Reduction Reaction

Abstract Low‐cost and high‐efficiency oxygen reduction reaction (ORR) electrocatalysts are the basis for large‐scale applications of electrochemical energy storage and conversion technologies such as fuel cells and metal‐air batteries. Herein, cobalt and oxygen vacancy‐rich cobalt oxide encapsulated in nitrogen‐doped carbon and carbon nanotubes (Co/CoO@NC‐CNTs) have been prepared by direct solid‐state pyrolysis of Co‐MOF. The carbon morphology, oxygen vacancy content and type of nitrogen can be finely tuned by mixing Co‐MOF with proper amounts of melamine. The optimized material has an interwoven CNT structure with abundant micro‐ and mesopores, suitable nitrogen type and certain number of oxygen vacancies and exhibiting outstanding ORR electrocatalytic performance in alkaline media with an onset potential of 0.96 V and a half‐wave potential of 0.88 V vs RHE, which is higher than 20 wt% Pt/C, as well as being highly stable and well resistant to methanol.